Best subwoofer below 40Hz for Magnepan .7?

From what I understand the Loki is a Baxandall type tone control, covering a pretty wide range, whereas a system like the Antimode (or an REW corrrection curve) is a very precisely targeted precision weapon. And it is very small indeed. Mine just sits behind my power amplifier, out of sight and out of mind.

What about the multi sub system from Audiokinesis called Swarm? Might be the answer...

Can anyone tell me how a multi sub config is connected to the amp?
I can understand 2 subs, but 3 or more? 
B

Excellent advice and ideas…gotta love this forum.

My listening room is 20’ X 28’ X 9’, and it has an additional 7’ behind the speakers with stairs to a lower level. I have no boomy issues, so perhaps the stairwell acts as a trap for low frequency reflections (that’s using my second set of speakers, which have SEAS 10” bass drivers and extend below 30Hz).

I agree that RELs and JLs are fast enough, while big and slower drivers (15”) might not work well. I’m going to demo Martin Logan’s 210 in a few days, and I’m interested in the Vandersteen 2WQs, which are new to me. Also interested in Antimode 8033 which I don’t know at all.

The Maggies deliver plenty of detail, but in my (new) experience they need to be played loud to bring it forward, so I may rethink this, as some have suggested here.

Thanks everyone.

"The" best? That's easy: the GR Research/Rythmik OB/Dipole Sub. A dipole speaker with a dipole sub---how ya gonna beat that?! And one employing servo-feedback ta boot!